There is an active group designing games for the P3 platform from Multimorphic.
https://www.multimorphic.com/p3-pinball-platform/3rd-party-developers/

That platform seems ideal for bringing your game to fruition.

Some relevant threads:
https://pinside.com/pinball/forum/topic/p3-module-join-me-in-development
https://pinside.com/pinball/forum/topic/multimorphic-p3-club
https://pinside.com/pinball/forum/topic/new-game-reveal-monday-from-multimorphic
https://pinside.com/pinball/forum/topic/p3-game-ranger-in-the-ruins

Wow, there is a lot to go over in your google doc, but I like what I've seen so far.
Inevitably, you are going to do some trial and error with your playfield, figuring out what works and what doesn't. You'll probably have several versions of your playfield.
You're the one who knows best what end result you're looking for. It's a bit hard to give you guidelines of how to design a playfield because there are no rules to playfield design, especially with homebrews. Just try experimenting with shots on paper or vpx or photoshop or whatever you use. Play around with it until you have something you like.
One last thing, if you really like the layout or a certain shot on a machine that already exists, get inspired by that. Make a shot and/or mech on the playfield to work around, you'll be surprised how quickly the rest will fall into place.

What he said!

If you go P3 You only have to design the back third of the play field with the front 2/3 taken care of by the platform. It’s a quick way to get going particularly for someone strong and software and can leverage the unique features of the P3.

You have a large wish list for elements you would like to put in the game. I would put prioritizing this part of the design front and center and work your theme around what’s fun to hit and within your skills to build. If you are going with a traditional machine format, the first decision will be the playfield and cabinet width. Will you be cannibalizing another machine for the cabinet? If so, that sets your width. Generally, widebody machines tend to have a slower feel to the game, although active elements in the lower play field or an increased slope can change that. An early decision will be how many ball paths will lead from the mid playfield to the upper play field. I’ve found that paths less than 1.5x ball width are very difficult to hit and 2x width a practical minimum for my playing skill. Between each ball path will need to be a post or target which also gobbles up width. These will be primary constraints on your geometry. One thought I have about the theme, the blocky pyramid Architecture is at odds with the sloping nature of pinball ramps. To me, this calls out for an upper play field being the top of a pyramid (or plaza) with a ramp hidden on the side. Pops can be trees and jungle. A toy that drops into the mid playfield ghost busters style gains you a removable target. These are just ideas worth what you paid for them. Oh, how are you controlling? Multimorphic, FAST or cobra? MPF?

In my opinion, the best way to start building machines is to start building a machine. Doesn’t matter if you start with foam core and tape, or plywood and posts with rubber bands. Just go build your first playfield. You can do this with a reasonable investment, and you will learn a ton. Get a drill and pop some lights through the playfield in the old Bally style. Modify it to understand angles. Then flop it aside and build another, but using your new skills you learned on the first.

When you build something, no matter how bad, it teaches you how to build your next.

For me, I got into my second build and realized it wasn’t fun. I love repairing them, but building from scratch just isn’t my jam.

I'd skip the P3 module.. I love the platform but that really only makes sense if you're also going to invest in a P3.. and they ain't cheap You've got a lot of solid ideas down -- if you really want to maximize what you incorporate than I agree that a wide body is the way to go... that said, you're spending THAT much more time getting the layout worked out, more $$ on mechs & electronics & parts probably, and in the end a slower game. Guess it depends how much time you expect to put into this and if you like wide body machine play or want something faster.. Also with wide body there's less donor cab's available so you might be looking most definitely at buying new (I think virtualpin does wide bodies?) or building yourself.

You've got a lot of elements and wishes for a first homebrew. Take whatever time you think this will take and multiply by like 3 (at least) lol. Same with $$.

Sounds like you're ready to start building a foamcore though. Decide on wide or standard and go for it! Cut a blank piece of ply and start hot gluing foamcore and cardboard, go nuts! Even better if you can decide on a boardset first, and get the lower 3rd in so you have working flippers and slings to shoot balls around while you test things out and move things.

As mentioned - shots are really limited by that ball width factor + whatever protective element or target that sandwiches them.. so realistically on a standard game with a fan layout I think most get between 6-8 shots if I remember right? Upper playfield is slightly easier than the lower.. the windows for lower playfields are a bit of a pain to deal with. certainly doable though.. just not sure how fun they are for the effort.

Love the starmap in the backglass area with spinning discs. I'd ditch the apron LCD and just track relics with inserts. Once you get 1/2 thru, you may find yourself ditching some overly ambitious ideas like the ropes and apron LCD.

Have you seen the "Escape from the lost world" pin? You should check it out.. I could see something similar on yours with an upper playfield shot thru a backboard.. and if you had a bridge like escape.. that is a FUN shot when you make it! Does take up some space though.

Look into a 3d printer if you don't already have one. It's nice to have spare mechs on hand too.. I'd make a big order from pinball life and pick up a target, sling stuff, 2 full flipper setups, maybe a rubber kit, some posts, and a few things you'll likely use but don't know where they go yet. Having them as reference for size is really nice.. then you can mock up accurately with foamcore.

Most importantly - don't forget to document your journey here! Love following Homebrew threads!

I’m a designer, not of pinball machines, but of video games and other things. The best advice I can give is that design is iterative. It’s like making soup. You need to build something (prototype), try it (taste the soup) and if you are a good judge of taste you will know what needs to change. So relating to your question of what should come first: theme, ideas, or layout, the answer is kind of none of the above. You should have some general ideas about all of that, build something and try it, and that will inform all of it. You will find theme will influence layout, layout might change your theme somewhat, you will come up with new ideas while prototyping. In a creative process one may make dozens of prototypes each getting more refined and closer to a cohesive experience. With the physical labor of making actual playfield prototypes maybe that many isn’t feasible, but the main point again is that it’s an iterative process and not linear. Good luck!

I'd personally agree with most everything said. Just start building. The pool of ideas to draw from is good inspiration, but I found while building Spaceballs that a lot of my ideas ended up being tossed once I started actually implementing them.

I personally used FAST and MPF, which I recommend, but you can build a pinball machine successfully with the others also.

My #1 suggestion? Enjoy it! Don't make yourself beholden to deadlines or anyone else. It's your game, have fun with it. There may be weeks or months you don't feel like working on it. That's normal and don't beat yourself up over it. It's a long process.

ENJOY IT!

We got some of the details documented here: https://docs.missionpinball.org/en/latest/physical_building/index.html

Have you heard of Cobrapin? Instead of having to buy 4+ boards for multiple hundreds of dollars, it's all contained one one board. cobra18t sells them here on pinside I believe.
Also, Visual Pinball is a fantastic program for prototyping playfield digitally. You can put all the usual mechs on a playfield and then actually play the game to see if the flow works! As a software guy this should be right up your alley. It's not perfect, but it helps you get a decent idea about what layouts may work, how wide ramps/shots need to be, how difficult shots may be, etc etc

I used multimorphic boards on my home brew, my current project and plan to for my next one in the early design stage. I like that board set because it is well supported in Skeleton Game and MPF with native support for steppers and servos. Very robust.

I have found the FAST pinball system to work very well, and it's pretty straightforward. P3 and cobrapin will also work fine, each system has pros and cons.

I think whatever boardset someone started with, they are likely to recommend because they all seem fairly similar and few issues so far with any.. Cobrapin def. has a good price point, but the limitation is that if you need additional drivers or switches you need to buy another cobrapin board which I believe is more expensive than adding a multimorphic or FAST specific switch/driver board.

FAST <--> Multimorphic .. there's some cost difference depending on how many LEDs, drivers, and switches you want. With FAST - the LEDS are all serial, so if one starts to flake out it tends to affect others down the line. Multimorphic allows a hybrid LED system so some can be parallel and some in series.. but I believe you have to buy driver boards for them whereas FAST has 256 channels built into the main NANO board. I personally went FAST and am very happy with the system.

Sounds like a wide body could work for you. If you can find the Doom custom pinball on youtube, check that out. (It might only be on a thread here, not positive).. that's one of the few very detailed wide bodies I've seen done homebrew. I could see it being similar to what you might want.. swap the theme and graphics and such, add an upper playfield. Even upper PFs - it's hard to make them fun though.. (see about every game Spooky has done). Course some people love em and some hate em.

If you have trouble coming up with a layout and you want one that "just works":

- Go to the Stern website (or any other company, but Stern is the most consistent for this), pick a game you like.
- Download the manual.
- Import it in Photoshop/GIMP.
- Choose a page with the shots visible, crop the image to the playfield size.

Now you can mark the position or angles of the shots you like, what you want to change, where you want to place cool mechs or whatever you want to do.
You can also repeat the process and overlap the images into one, so that e.g. you pick the center ramp on Aerosmith, the left drop targets on AIQ, the right scoop from GOTG, etc.

-----

Here are 2 examples for so you see what I mean with this process: I exported the cropped playfield and imported them in Future Pinball, then I just messed around and made a layout:

pasted_image (resized).png
pasted_image (resized).png
This was made (not completed tho) with the Star Wars and Batman '66 manual. For Star Wars, I kept the position of the left ramp, and the angle of the right ramp (but I moved it further down). Then for B66, I liked the spinner shot that sort of stops dead, so I copied it. The left ramp is now a loop. I just copied the right loop and the TV targets as well. The rest is filler.

pasted_image (resized).png
This is from recently when I tried to make a Houdini clone with one less shot, but it was the same process.

Or you could use FadeCandy with MPF and P3 (or other controllers)

I was overall pleased with the P3 boards I’ve used.

I started my homebrew and the question I keep asking myself is going Williams or Stern? For now I just decided go with the old 20.25 x 42 because I would have more choices for a old used cabinet. Also it would be easier work up to a bigger size.

I'm Not sure If the 3d cad Templates for the lower third are fine. But all Templates have different Dimension for the distance between holes.

On one the the left outlane ist to Close to the end of the left playfield Side (3,25mm). Or there ist No shooterlane or the Flipper holes are to Close (about 156mm)

Any Chance someone has a Template for working lower third of a Stern machine with right Dimensions or an Overview for the correct Dimensions.

Also it's pretty hard for me to Come along with the right Return Lane Guides and the holes in the Templates

Are you making your own cabinet or reusing a scrapped one?

If you’re building one you probably want to go with a WPC wide body dimensions so you can more easily get the right cabinet parts

following

There is actually a satellite board that adds more switches, drivers, lights, etc. Only an additional 45. Main board is 175. Just got mine so can't really vouch for them yet.

Good to know! That’s a great deal. I almost pulled the trigger on the startup deal but decided to stick with fast fir my future project just to be able to have 1 set up backups

Steve used to make custom pinball cabs. Not sure if he still does but you could check to see if he might know a local source. Durham is semi-local for you.

https://zebsboards.ca/

Also my 2 cents:

- Making a custom pinball is a really, really, really long process. There are so many skills to learn if you are doing it by yourself. I am still trying to complete one 8 years later and I am doing a retheme which means I don't even have to deal with CAD, designing layouts or custom mechs, ramps and other pieces. I figure if I can complete this, then a 100% custom one will be next.

- MPF has come a long way and is pretty much fit for purpose for any game these days. It is even being used in commercial machines now. Jan and the other regular contributors have made it a great framework and its open so you can add your own custom code if you hit a wall. As well, its hardware agnostic so if you ever do change, you won't have to rewrite the code. I know of a few homebrews using MPF that switched hardware and they didn't have to deal with changing their software.

- Any boardset will pretty much work. OPP/P-ROC/Cobra/FAST etc.. I chose FAST and have been super happy with the support of Aaron/Dave and the community around it.

- Throwing every idea into a game is not the best approach. Like the food reference, you can't throw every spice into your recipe. Sometimes less is more.

- Have fun. Its not a race, unless you make it.

The actual layout is a relatively small portion of the huge amount of work to be done.

Focus on one or two big ideas, do them well, and the rest of the layout will coalesce around those elements.